Multistage turbine.



umneamm. MULTISTAGB TURBINE. APPLICATION IILED MAY 28. 1904- PATBNTED OCT. 30, 1906.

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PATENTED OCT 30 0; JUNGGREN. MULTI STAGE TURBINE.- APPLICATION nun 128.1904.

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UNITED STATES PATENT ornion OSCAR JUNGGREN, OF SCHENECTADY. NEW YORK, ASSIGNOR GEN- ERAL ELECTRIC COMPANY, AOORPQRATION OF NEW YORK.

MULTISTAGE TURBINE.

Specification of Letters Patent.

Patented 0011.30, 1906.

' To all whom, it may concern.-

Be it known that I, OSCAR JUNGGREN, a citizen ot the UnitedStates, residing at Schenectady, county of Schenectady, State of New 5 York, have inventedcertain new and useful Im rovements in Multistage Turbines, of which the following is a specification.

Multistage turbines of the jet or impact type as ordinarily constructed have either lo one or more rows of wheel-buckets per stage,

with nozzles for converting the pressure into velocity and discharging it against the buckets. When constructed with only one row' of wheel-buckets, it necessitates a diaphragm This construction involves a large number of diaphragms or"separatingwalls, which, in addi tion to being expensive to construct, increase the longitudinal dimension of the turbine, be-

sides adding greatly to the weight. When constructed with two or more rows of wheelbuckets per stage, intermediate buckets are requiredbetween each tworows of buckets. These intermediate buckets receive motive 2 5 fluid from one row of buckets and after changing its direction discharge it at the proper angle against the adjacent row of buckets, and so on; Since these buckets act merely as directing ,devi'ces, they consume a certain amount'ot energy, and therefore represent a.

loss in efiiciencv. y

The present-invention has forits object to improve the construction of elastic-fluld turbines, whereby the advantages of stage oper- 3 5 .ation are obtained without the disadvantage of using .a large number of diaphragms, on the one hand, or a considerable number of intermediate'buckets, on the other.

In carrying out one form of m invention 40 a suitable casing is employed w ich is pro-' vided with one or more diaphragms between the high-pressure stages, wherein the'diflerence in pressure is considerable. In .these stages one or more rows of wheel-buckets are 4 5 provided for'abstracting energy from the motive fluid delivered by the preceding nozzle. Where two or more rows of wheel-buckets j are employed in each stage, a row of intermediate buckets is provided, which cover the necessary number of wheel-buckets. 1 prefer to so arrange the parts in this particular embodiment of the invention that the wheels I separated by the diaphragm or walls abstract the energy of the motive fluid represented by the drop 1n pressure from the source of supply to atmosphere; but theinven'tion is not to be construed as so limited, since the drop in pressure may be greater or less, as is best suited to meet the conditions of service. In

I the construction described the high-pressure nozzle or nozzleshave a greater ratio of expansion than the low-pressure nozzles, the ob ect being to reducethe stage-pressure to a point where the strains on the casing are well within the safe working limit. This results in a somewhat higher velocity of the motive fluid in the hi h-pressure stage or stages, and, for this reason a greater number of rows of wheel-buckets is employed therein than in the low-pressure stages.

The low-pressure portion of the machine, or that designed to Work between the terminal pressure of the stages above referred to and the exhaust, whether it be atmospheric or that due to a condenser, is of special con struction. As many wheels or rows of wheelbuckets are provided as are necessary to fractionally abstract by stages the remaining energy due to the difierence in terminal pressure-s. .The buckets may be arranged on a drum in concentric rows, or they may each be mounted on a separate wheel and the several Wheels connected by cylindrical flanges formed thereon or by rings which are located between the wheels. The main considerations are to cut off the space between the wheel-webs to form chambers, to strengthen the rotating member as a whole, and to reduce the cubical contents of the surrounding chamber as much as possible. This'arrangement is also highly advantageous, in

. that it prevents individual movement of the wheels in any direction. Situated adjacent to each row of wheel-buckets is a ring which extends around the wheel and contains one ormore nozzles that imp art a certain amount of velocity to the ste am or other elastic fluid and discharge it againstthe buckets." Each ring, in addition to containing or carrying the nozzle or nozzles, acts as awall which cooperates with a wheel to form a stage or wheel compartment. As shown, the nozzles or nozzle sections or passages are formed in the ring-like structure which surrounds the wheel; Each nozzle-orifice may be provided with a well-rounded bowl anterior to the the clearances. nozzle-orifices on while the nozzle or nozz zle, in order to escape from one com siderations will prevent.

throat, or several orifices may be grouped together and supplied from a single bowl. The nozzle-passages between the throat and the discharge-orifice may be expandingor nonexpandmg in character. This depends largely on the desired velocity of the fluid stream. The ring-like structure in which the .nozzles or passages are formed or supported is seated on a shoulder on the casing and is retained y suitablemeans located inside or outside of the casing, formed integral with the inner wall of the casing, in which case it would artake of the nature of a shoulder. When ormed integral with the casing, the latter would of necessity be made in sections. The are of the wheel covered by the nozzle-orifices increases from the inlet toward the exhaust, the last orifices covering the total or practically the total bucket area of the wheel. It is desirable to utilize the total bucket area of the wheel, since this wheel is the limiting feature in the design; but in some instances structural con- On the other hand, it may be desirable to leave soine space to form a passage to balance the pressures on opposite sides of a row of buckets and their support. The portion or portions of each ring betweenthe nozzles or nozzle-sections is left blank, so that a wall is formed which will restrict the passage of motive fluid through The metal adjacent to the the shaft side also acts as a part of the wall for separating one wheel-compartm'ent from the next. In other words, the clearance between the wall and buckets or wheel-body forms a hi h-resistance path,

e sections or passages and the working passages between buckets forms a low.

It is further to be noted. that any fluid, exeluding that which passes through the nozpartment to the next inust pass through the buckets, and while it may not do the maximum amount of work it will do some, and in this manner even the leakage ismade use of.

Another advantage residing in the use of these rings is thatv the plane flat surf ces of the wall between and adjacent to the discharge-orifices act to reduce the rotationlosses.

As an illustration, with the structure re-.

ferred to a turbine having six or more stages can be made with only two diaphragms and two sets of intermediates.

\Vhen owing to the s ecial arrangement of parts a considerable di ference in pressure exists between opposite sides of the low-pres sure portion of the turbine, I may provide one 'or a number of valved or unvalved conduits for equalizin the pressures wholly or in part. These va ves may be operated automatically or by hand, as preferred. In this form of my invention the pressure between as desired. If desired, it can be or having nozzles formed therein,

.compartments thus formed phragm altogether.

stages is equalized by sections-that is to say, one portion of the revolving element of the turbine is largely balanced by another.

, In another embodiment of my invention I divide the high-pressure portion of the turbins-casing into stages by one or more diahragms which contain or support nozzles. In the compartments thus formed are placed wheel structures of the same or substantially the same construction as previouslydescribed. Between each two rows of wheel-buckets is situated a ring-like support carrying nozzles which suports and nozzles operate in the manner set Forth above. Where the difference in pressure on opposite sides of the wheels is-too great, the wheels may be perforated at one or more points;but I prefer not to do so on account of leakage. With this construction the intermediate buckets are entirely dispensed with.

Themodified construction just described has this additional advantage: that the wheel or wheels as a whole can be lowered a sufficient amount by droppin the step or thrust earing in a vertical machine or moving the shaft longitudinally in a horizontal machine to compensate for any wheel or casing distortion which may exist. In the first-mentioned arrangement involving intermediates the longitudinal movement of the shaft is'of course limited by the small amount of the clearances. A turbine constructed according to the second modification of my invention can be divided into eight or more stages with the use of only two diaphragms and without intermediates.

A further embodiment of. my invention contemplates dividing the turbine-casing into two compartments by means of a single wall or diaphragm and subdividing the by arranging a number of rows of wheel-buckets on a suitable support after the manner described. Between each two rows of wheel-buckets is placed a nozzle of the same as before, the cross-sectional area of the nozzle dischargeorifices increasing from the supply toward the exhaust. The arrangement of the parts is such that each nozzle is arranged in a compartment by itself and the motive fluid is renozzled every time it passes through a row of buckets. By using a single diaphragm the end pressure or thrust to which the shaft would or might be subjected is reduced. In the construction just described the effect of an eight-stage machine is obtained with only a single dia hragm. In certain cases as, for example, w ere the tendency to end thrust com ensating means are rovided, such as would be the case where t e end thrust on one part of the machine balanced the other part Wholly or partially-I may omit the dia In this latter case the is small or where IIO general character arrangement of the nozzles and buckets revolve in one direction and the remainder in the opposite.

In. the accom anying drawings, which illustrate one fem odiment' of my invention, Figure 1 is an axial section of a vertical turbine of the jet type. Fig. 2 is a partial axial section of a turbine, illustrating a modified construction wherein .the intermediates are dispensed with. 'Fig. 3 is a sectional View of a further modification wherein only a single diaphragm is employed, and Fig. 4 isa secional view of a art of a turbine. I

, Referring to igfl, 1 represents the casing of a machine, which is mounted. upon a base 2, the latter containing a chamber 3, which is connected to or forms a part of a condenser.

4 represents a conduit for conveying the exhaust from the machine. The upper end of the casing is provided with a cover or head 5, which is bolted or otherwise secured to a casing; The shaft 6 is disposed vertically, and mounted thereon are high-pressure wheels 7 and 8. These are'separated by a diaphragm 9. The wheel 8 is separated from the lower-pressure wheels by a dia-- phragm 10. Situated. below the diaphragm 1.0 are low-pressure wheels 11. Each of these wheels is provided with a cylindrical projection 12, that forms a part of a wall to cut off the space 13 between the wheels from the surrounding chamber. As many of these wheels are employed as are necessary to abstract the energy from the motlve flu d.

The end wheels are provided with a cylindrical wall 12 on one side only; but the other wheels are provided with these walls on both sides. The wallon one wheel is rabbeted into the corresponding wall on the other. wheel. Extending axially through the wheels and the cylindrical walls are retaining-bolts 14 or equivalent devices. Each of thelow-pressure wheels is provided with a single row' of buckets 15, the buckets being provided with integral projections, which .entera groove in the periphery of the wall and The are retained in place by pins or bolts.

upper row of buckets is situated directly under the diaphragm 10 and receives motive fluid from the nozzles formed therein or supported thereby. Mounted below the first row of buckets is a c lindrical or ring-like structure 16, which is ocated"'in close proximity to theupper side of the row, of buckets 17 and also to the upper side of the wheel-body. In the cylindrical or ring-like structure or carried thereby are nozzle assages which receive motive fluid from t e preceding wheel the bucket 17.

:and after converting a certain amount of the pressure into velocity discharge it against the nozzle-orifices is made as smooth as possible, so as to cooperate with the upper side of the wheel and t e buckets to form a stage.

structure just referred to, which is located in close proximity to the wheel-buckets, is givenreference-numeral 18. In addition to forming a art of the stage the cylindrical structure a so tends to reduce the rotationlosses by presenting a smooth surface in close proximity to the wheel-buckets. The succeeding ring-like structures 16 after the first are of the same construction and-operate in the same manner, the exception being that the nozzle area increases in each succeeding stage. I 1

In case of a material difference in pressure between the first and second stagesof the low pressure portion of the turbine or between other portions a conduit 19 may be provided,

which communicates with the upper sideof The nozzle or orifices in this I The portion of the cylindrical or ring-like the first-wheel and with the under side of the second succeeding wheel. duitmay/be provided with a valve 20 or not, as desired. I

It is to be noted that the high-pressure stages are provided with two rows of wheelbuckets, while each of the lowressure stagebuckets is provided with on y one row of wheel-buckets. In the former case intermediate buckets 21 are provided for reversing the direction of the motive fluid between the buckets. Steam or other elastic fluid is suppliedto the turbine by inlet-nozzles 22,

which cover only 'a fraction of the bucket area.- These nozzles are supplied-with fluid from the chest 23, and the passage of fluid to the nozzles is controlled by a plurality of separately-actuated valves 24, each of the valves being independent in its 'action of every other valve and responding to changes in position of a spfiled-responsive device. I

may control only e supply of 'motivefiuid to the first stage, or I may control the supply to the first stage and also to one or more of the succeeding stages.

In Fig. 2 I have shown a modification of my invention wherein the use of intermediates is entirely obviated. The construction of the wheels is the same as'that described in connection with the dew-pressure wheels of the turbine shown in Fig. 1, exce' t that openings or passages25'are provide for equalizingthe pressure on the op osite sides of the wheels. In some cases t ese openings or passages can'be omitted, and wherever it is possible I prefer to do so. Between each two rows of wheel-buckets is a ring-like structure 26, which coo crates with the up- .per side of the rows 0 wheel-buckets and The conthe body of the wheel to form a stage. This ring-like structure also contains -nozzle pas sagesor has nozzles bolted or otherwise .at-

tached thereto. ,A modified form of inletnozzle is also provided, which nozzle extends through .an opening in the side wall of the casing 1 and is provided with an outside flange 27. The nozzle isheld in place by bolts 28, which extend throughslots in the flange, the object of this arran ement being to permit the nozzle to be a justed in an .axial direction. Steam or other motive fluid is supplied to the nozzle by the conduit" 29. I may provide each of the nozzle-sec' tions with a valve or not, as desired.

In the present embodiment of the invention only two diaphragms and 31 are provided. In this instance the first four rows of wheel-buckets are contained in the highressure portion of the turbine, while the ast four are contained in the low-pressure portion. With this arrangement I get theadvantages of an eight-stage turbine with only two diaphragms.

In Fig. 3 I have shown a modification wherein .only one diaphragm 32 is provided,

. which diaphragm is similar in construction to those previously described-and which may divide the turbine into parts at the atmos- ;made in a single piece or of sections.

pherical line. Steam or other elastic fluid is suppliedito the first wheel by a nozzle'33 of the same general construction as described in the previous figure. In this case, as in Fig. 2, the intermediates are dispensed with, sothat the wheel structure as a whole can be adjusted vertically overa considerably wider range than where intermediate buckets .are employed. This arrangement is advantageous in those cases Where for any cause there is excessive distortion of the wheel,

1 taken down.

In Fig. 4 is shown a desirable arrangement for the head 5- or diaphragm or wall be- .tween stages, where such .a construction is employed. It is situated in close proximity -'to the web of the wheel, thereby cutting down the cubical contents of the chamber as much as possible and also reducing the rotation losses.

To. the wheel-chamber at a point near the shaft is connected a conduit 35, which discharges into a wheel-compartment'of lower pressure, preferably the adj acent compartment, so as not to .have too great a pressure difierence. This conduit will tend to equalize the end thrust on the rangements previous s am shaft. It is ofreven'greater use with the constructions employing the rim dike-nozzle arydescri ed.

'In accordance with the provisions of the patent statutes I have described the principle of operation of my invention, together with the a paratus which I now consider to re resent t e best embodiment thereof; but I esire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

What I claim as new, and esire to secure by Letters Patent of the United States, is

'1. An elastic-fluid turbine comprising a casing, rows of wheel-buckets, and inlet-nozzles, in combination with wheel-webs for carrying the buckets, a cylindrical wall on each web which unites the rows of -wheelbuckets, a ring-like structure which extends toward the wall but does not contact therewith, the said structure cooperating with a row of wheel-buckets to form a stage, and expanding nozzles in said structure which convert the fluid-pressure in one stage into velocity and discharge it against the wheel-buckets in a stage-of lower pressure.

2 In an elastic-fluid turbine comprising a casing, rows of buckets, and inlet-nozzles, in combination with wheel -webs'or bodies for carrying the buckets,v cylindrical walls on said webs' which engage one with the other,

means for clamping the wheel-webs'together,

a ring-like structure which extends between adjacent rowsof wheel-buckets and cooperates with one of the rows to form a stage, and a nozzle for discharging fluid against the row of wheel-buckets cooperating with said structure.

3. In an elastic-fluid turbine, the combination of a casing, a shaft, bucket-wheels mounted thereon, means for dividing the easing into compartments or stages in such manner that a high-pressure compartment or stage contains more rows of wheel-buckets than does a low-pressure compartment or stage, intermediate buckets for the highpressure sta e only, and nozzles for discharging fluid un er a predetermined condition as to pressure and velocity against the wheelbuckets.

' 4. In an elastic-fluid turbine, the combination of a casing, means for dividing it into compartments or stages, wheel and intermediate buckets located in .a high-pressure stage for fractionally abstracting energy from the motive fluid, a single row of wheelbuckets in each of the lowressure stages, and nozzles for discharging uid against the buckets of the diflerent stages.

5. In an elastic-fluid turbine, the combination of a casing, a diaphragm which divides the easing into compartments, wheels carrying buckets located in the compartments, ringssupported by the casin which. cooperate with the wheels to divi e the compartments into additional compartments, and nozzles which convert the pressure of the motive fluid into velocity and discharge it against the'wheel buckets. v a v 6. '.'In an elastic-fluid turbine, the combination of a casing, a diaphragm which divides the'casing into com artments', wheels carryin'g buckets locate in the compartments rings supported by the casing, the wheels an rings cooperating .to form stages and presenting smooth flat surfaces to each other partments and is supported at its periphery y the wheel-oasin and is provided with an orifioe'to receive t e hub of a wheel rings which are supported by the casing,

and coop- 'erate with the wheels at points remote from the hubs to form stages and also to reduce the rotation losses b presenting smooth surfaces to the idle buc ets, and noz zles for discharging motive fluid against the wheelbuckets.

8. .Inan elastic-fluid turbine, the combination of a casing, a'diaphragm which divides the casing into high and low ressure com-- partments; a plurality of rings ocated within the casingon the lowressure side of the diaphragm,'wheels'for t e high and low compartments, the wheels in said low-pressure compartments'cooperating with surfaces on the rings to form' low-pressure stages, admission-nozzles, and nozzles which receive m0- tive fluid from one stage and discharge itagainst the wheel-buckets in another stage.

In witness whereof I have hereunto set my hand this 26th dayof May, 1904.

' OSCAR JUNGGBEN. Witnesses: i

EDWARD WILLIAMS, Jr., HELEN ORFORD. 

